A study on insertion-loss improvement for optical connector using the analysis of transmitted optical intensity

In the butt-joint coupling using cylindrical ferrules and sleeve, the insertion loss of the single-mode optical connector depends on the accuracies of components (i.e., sleeve, ferrule, fiber etc.). And it is difficult to achieve both cost reduction and performance improvement simultaneously in optical connectors because higher accuracies give better performance but cause higher cost. For single-mode fiber connection, the dimensional accuracies of currently available ferrules and optical fibers are not sufficiently high to ensure a low insertion loss with reasonable cost. And many efforts have been made to have low insertion loss without any higher order of accuracies of components. In one of the proposed methods the technique of stepwise orientation of ferrule is used to reduce the transverse offset between butt-joint fiber cores by achieving Minimizing Loss Region (MLR). This method requires several stepwise rotations to make the fiber core be within the MLR that was determined by optimal trade-off between insertion loss and working time. In this method the insertion loss depends on the size of the pre-determined MLR. In the report a new assembling method through which a very small MLR can be achieved in a short time is proposed